1. Field of the Invention
The present invention relates to a method of repairing a coke oven buckstay and a moving device for use in such method.
2. Description of the Related Art
The coke oven buckstay is a reinforcing part that supports coke oven walls and that is provided for eliminating the problem of the oven walls breaking or collapsing as a result of expansion of bricks forming the oven walls.
FIG. 1 is a perspective view of what is called a chamber-oven-type coke oven. The coke oven comprises carbonization chambers 52 in which coal is carbonized; combustion chambers 54 in which fuel gas is burned; and a regenerating chamber 59 for pre-heating the fuel gas and combustion air by making use of heat left in the exhaust combustion gas. The carbonization chambers 52 and the combustion chambers 54 are alternately disposed on the top portion of the regenerating chamber 59, forming a group of component parts of the oven. The coal, which has been put into the carbonization chambers 52 by a coal-charging car 51 that moves on the top portion of the coke oven, is carbonized as a result of being subjected to heat from the combustion chambers 54 located on both sides of the carbonization chambers 52 corresponding thereto. Oven doors 58 and 60 are removably disposed on each end of the carbonization chamber. After the oven doors 58 and 60 of the carbonization chamber 52 have been opened, the carbonized coal, that is, coke is pushed out by a pushing ram of pusher machine 55 through a guide car 56, and transported to hot coke quenching facility (not shown) through a coke bucket car 53. Side 3, at which the pusher machine 55 is disposed, is called the machine side (hereinafter referred to as M/S), while side 4, at which the guide car 56 is disposed, is called the coke side (hereinafter referred to as C/S). The directions of a line connecting the M/S and the C/S are called the longitudinal directions of the oven, and the longitudinal directions are represented by a double-headed arrow 61. The directions in which the combustion chambers 54 and the carbonization chambers 52 are arranged are called the widthwise directions, and are represented by a double-headed arrow 62.
FIG. 2 is a sectional view of the coke oven as viewed perpendicular to the longitudinal directions thereof. At the outer sides of the coke oven are disposed M/S and C/S platforms 11a, 11b along the widthwise directions thereof. These platforms 11a, 11b are used when, for example, maintaining the oven doors 58 and 60 in an open position. On the top portion of the C/S platform 11b are disposed rails 12 on which the guide car moves. Below the M/S platform 11a are disposed rails 22 on which the pusher machine moves. As shown in FIG. 2, the coke oven is formed by oven walls 2 formed by placing a plurality of layers of fire-resistant bricks (hereinafter simply referred to as xe2x80x9cbricksxe2x80x9d) upon one another. Pillered steel members or buckstays 5 are disposed vertically in a standing manner at the M/S and the C/S of the oven walls 2 so as to hold and compress them. Tension rods 6 are disposed at the top and the bottom ends of the oven walls 2 disposed at both ends of the coke oven extending in the longitudinal directions thereof. The tension rods 6 are secured to the buckstays 5 with bolts from both ends thereof. The directions in which the securing forces act are represented by arrows 31. Here, the bolts are sometimes secured through springs 7a provided at the ends of tension rods 6. (The securing of the bolts is hereunder referred to as xe2x80x9csecuring of the ovenxe2x80x9d.) Outward deformation of the buckstays 5 may be reduced by pushing in an intermediate portion of the buckstays 5 in a direction opposite the platforms 11a, 11b by the springs 7b from respective frames of the platforms 11a, 11b. 
However, when the coke oven has been in operation for a long time, the C/S buckstay 5a may become deformed, as shown in FIG. 3. When this occurs, the coke oven is less properly secured because the bolt-securing forces are not applied to the bricks. The reduced securing forces cause severance and misalignment of the joints between the bricks making up the oven walls. Gaps are produced between the various fittings and the bricks. This results in poor environmental control and undesirable conditions which result, for example, when gas, produced by carbonization of coal, leaks from the gaps between the fittings and the bricks, and black smoke exhausts from a chimney of the coke oven. In addition, increased deformation of the oven body or the buckstay 5a results when carbon that has adhered to the severed joints of the bricks grows excessively. To overcome the above-described problems, the operation of the carbonization chamber near the combustion chamber 54 at the location of a considerably deformed part of the coke oven (such as the buckstay 5a) is stopped. Other parts may be kept in operation while the damaged parts are replaced. At the same time that the replacement is being carried out, the bricks of the coke oven may be re-stacked.
FIGS. 4A to 4C illustrate a conventional method of repairing the buckstay of the coke oven. The procedure is as follows.
As shown in FIG. 4A, a crane 38 is placed in front of the oven with the combustion chamber 54 at which a considerably deformed part is located. The crane 38 is usually disposed on the ground at a distance of at least ten meters from the oven in a horizontal direction. A boom 35 of the crane 38 is extended to a height that allows the buckstay 5a to be suspended. It is usually extended to a height of about 30 meters from the ground. As shown in FIG. 4B, the buckstay 5a is supported and secured to a binding jig 36 mounted to an end of the boom 35. At a location 37 that is about 500 mm above the platform 11, the defective portion of the buckstay 5a is cut away. Thereafter, as shown in FIG. 4C, the separated portion of the buckstay 5b is suspended by the boom 35 that has moved to remove it. After the removal, a new steel member is suspended by the crane and mounted and welded to the remaining undeformed portion of the buckstay in order to affix it thereto.
However, depending on the arrangement of the peripheral facilities of the coke oven, it is probable that a crane may not be disposed in front of the combustion chamber at which the deformed part is located.
Additionally, even when the crane may be disposed so as not to interfere with the peripheral facilities, the boom may not be able to extend to the platform at which the deformed part is located, thus replacing and repairing operations would be prevented. For example, the M/S buckstay 5 of the coke oven shown in FIG. 2 cannot be repaired. This is because, as shown in FIG. 2, collecting main 21, that are provided above each of the buckstays 5 as paths for allowing carbonization gas to flow therethrough, interfere with the boom of the crane.
Repairing operations are usually carried out while most unaffected component parts of the coke oven are in operation. Obviously, the combustion chamber at which the buckstay to be repaired is located and the carbonization chambers near this combustion chamber are taken out of operation during repair. Repairing operations must be carried out quickly to avoid costly down time. However, due to the above-described problems, it takes time to carry out the repairing operations. Therefore, there has been a strong demand for an improved repairing method.
Accordingly, in view of the above-described problems, it is an object of the present invention to provide a coke oven buckstay repairing method which can be carried out more quickly, reliably, and smoothly than the conventional repairing method; and a moving device used in such method. To achieve this object, the present inventor has assiduously conducted research. Preferred embodiments of the present invention are discussed below.
According to one aspect of the present invention, there is provided a coke oven buckstay moving device for replacing a defective portion of the buckstay, which is supporting a wall of the coke oven, with a replacement member, the moving device comprising: a main car which moves on the coke side platform or the machine side platform of the coke oven; a subcar placed on the main car, freely moving forward and backward in a lengthwise direction of the coke oven; and a securing means, mounted to the subcar, for holding the defective portion of the buckstay or the replacement member.
According to another aspect of the present invention, there is provided a coke oven buckstay repairing method whereby a defective portion of the coke oven buckstay is replaced with a replacement member. The method comprises the steps of: moving a main car that moves on a coke side platform or a machine side platform to an exterior side of the buckstay that needs to be repaired, forwardly moving a subcar disposed on the main car to a location near the buckstay that needs to be repaired, securing the buckstay that needs to be repaired, cutting off and removing the defective portion secured to the subcar, mounting the replacement member of the buckstay to the securing means mounted to the subcar, moving the main car to the previous location of the removed buckstay, forwardly moving the subcar, and mounting and welding the replacement member to the remaining portion of the buckstay at the location where the defective portion has been cut off and removed.
In the present invention, the subcar with securing means for the buckstay is placed on the main car, which can move on either the coke side platform or the machine side platform of the coke oven, so that the subcar can freely move forward and backward in the lengthwise direction of the coke oven. Therefore, the buckstay can be reliably and smoothly secured, removed and replaced, even when, for example, a crane cannot be used to repair the buckstay of the coke oven. Consequently, the deformed portion of the buckstay of the coke oven can be easily and quickly removed by cutting, and replaced with a replacement member in order to repair a buckstay on either the C/S or M/S of the coke oven.